A variety of monomers, oligomers and polymers containing ethynyl (acetylenic) and substituted ethynyl (i.e., phenylethynyl) groups have been reported. The ethynyl groups in the polymer are either pendent to the chain, in the chain or at the chain ends. Many of these materials have been used to prepare coatings, moldings, adhesives and composites [P. M. Hergenrother, "Acetylene Terminated Prepolymers" in Encyclopedia of Polymer Science and Engineering, John Wiley and Sons, New York, Vol. 1, 61 (1985)]. Good processability by either solution casting and/or compression molding has been observed for the ethynyl and substituted ethynyl containing materials. In general, thermally cured ethynyl and substituted ethynyl containing materials exhibit a favorable combination of physical and mechanical properties. Some ethynyl endcapped materials such as the Thermid.RTM. resins are commercially available (National Starch and Chemical Co., Bridgewater, N.J. 08807). Other systems such as acetylene terminated sulfones have undergone extensive evaluation as matrix resins [M. G. Maximovich, S. C. Lockerby, F. E. Arnold and G. A. Loughran, Sci. Adv. Matls. Proc. Eng. Ser., 23, 490 (1978) and G. A. Loughran, A. Wereta and F. E. Arnold, U.S. Pat. No. 4,131,625, December 1978 to U.S. Air Force]. Phenylethynyl containing amines have been used to terminate imide oligomers [F. W. Harris, A. Pamidimuhkala, R. Gupta, S. Das, T. Wu, G. Mock, Poly. Prep., 24 (2), 325, 1983; F. W. Harris, A. Pamidimuhkala, R. Gupta, S. Das, T. Wu, G. Mock, Macromol. Sci.-Chem., A21 (8&9), 1117 (1984); C. W. Paul, R. A. Shultz, and S. P. Fenelli, "High Temperature Curing Endcaps for Polyimide Oligomers" in Advances in Polyimide Science and Technology, (Ed. C. Feger, M. M. Khoyasteh, and M. S. Htoo), Technomic Publishing Co., Inc., Lancaster, Pa., 1993, p. 220; R. G. Bryant, B. J. Jensen, P. M. Hergenrother, Poly. Prepr., 34(1), 566, 1993]. Imide oligomers terminated with ethynyl phthalic anhydride [P. M. Hergenrother, Poly. Prepr., 21(1), 81, 1980], substituted ethynyl phthalic anhydride [S. Hino, S. Sato, K. Kora, and O. Suzuki, Jpn. Kokai Tokyo Koho Japanese Patent # 63,196,564. Aug. 15, 1988; Chem. Abstr., 115573w, 110, (1989)] and phenylethynyl containing phthalic anhydrides have been reported. Imide oligomers containing pendent substituted ethynyl groups [F. W. Harris, S. M. Padaki, and S. Varaprath, Poly. Prepr., 21(1), 3, 1980 (abstract only); B. J. Jensen, P. M. Hergenrother and G. Nwokogu, Polymer, 34(3), 630, 1993; B. J. Jensen and P. M. Hergenrother, U.S. Pat. No. 5,344,982 (Sep. 6, 1994)] have been reported. See also J. E. McGrath and G. W. Meyer, U.S. Pat. No. 4,493,002 (Feb. 20, 1996), J. G. Smith, Jr. Adhesion Society Proceedings, Vol. 19, 29-32 (1996) and J. W. Connell, J. G. Smith, Jr. and P. M. Hergenrother, Society for the Advancement of Materials and Process Engineering Proceedings, Vol. 41, 1102-1112 (1996).
High temperature resins are used in a variety of aerospace and non-aerospace applications. Generally these materials require high pressures (&gt;200 psi) to form adhesive bonds, well-consolidated moldings or fiber reinforced composite laminates. If these systems could be modified so as to retain the high performance characteristics yet be processable using resin transfer techniques, then the cost of manuacturing would be substantially reduced since an autoclave would not be needed.
It is a primary object of the present invention to provide novel phenylethynyl containing compounds that are processable via resin transfer techniques. These materials exhibit the proper combination of properties to allow processing under resin transfer molding conditions. In addition, upon thermal curing these materials exhibit sufficient thermal stability, toughness and mechanical properties so as to be useful as adhesives, coatings, films, filled and unfilled moldings and composite matrix resins in high performance applications.
Another object of the present invention is to provide novel polymeric materials that are useful as adhesives, coatings, films, moldings and composite matrices.
Another object of the present invention is the composition of several new phenylethynyl containing imide compounds.